Stair-tread.



C. B. JACOBS. STAIR TREAD.'

APPLICATION FILED 00T.1. 1909.

'w|TNEss`Es: 7 INVENTOR ATTURNEY UNITED STATES PATENT OFFICE.

CHARLES B. -'JA.COBS, 0F PORT CHESTEBQ NEW YORK, ASSIGNOR T0 MURRAY AND JACOBS MANUFACTURING COIIIANY, 0F NEW YORK, N. Y., A CORPQRATION 0F NEW YORK.

To all whom it may concern.'

Be it known that I, CHARLES 'B..Jaoos, a citizen of the United States, and a resident of Port Chester, lVestehes-ter county, State of New York, have invented certain new and useful Improvements" in Stair-Treacls, of which the following is a specification.

My invention relatesl to stair treads or similar tread surfaces, such as platforms, thresholds, fooibourds, etc., which have exposed edges upon which people tread.

It is desirable that' the surfaces of treads of this character shall have and be capable of retaining anti-slipping properties. It is particular-lv desirable that the surfaces of such treads at vor innnediately adjacent to the exposed edges thereof, 'at which slipping is most likely to occur and whichreceive the most wear,`shall have. and bc capable of revtaining antifslipping properties.. 'In 'other Words, the surfaces `of suoli treads, while being smooth enough to afford comfortable footway, should nevertheless be of such a nature that the footwear of pedestrians will .adhere thereto; and at the saine time such vsurface should be capable of resisting wear or abrasion without losing its adhering or anti-slipping properties, and the antislip slipping,

.small or sharp edges or corners 'as are ping and wear-resisting properties should extend to or practiea'llyto the'exposed edge of ,the tread so as to be effective to prevent where slipping is most likely to occur.

The invention has for its object to profI .I

vide a'tread which shall possessthese qualitiesin a. high degreeu This and other ob'- jects of the invention will in part be obvious and in part be vmore fully explained in the following description.

In accordance with one feature'of the in' .of such material and size that they will not be destroyed by the heat of the molten metal' when casting the'same, and such ele; ments being soclosely arranged as to protect the' softer material of the base from wear or abrasion and also to presentsuch adapted to partiall embed themselves in the contactin `sur aces of footwear and thus prevent s ipping, the said surface also being extended to the exposed edge'of the Specification of Letters Patent.

Application filed Octobel` 1, 1909. Serial No. 520,502.

sT'Am-TEEAD.

, tread or so close to the edge as to effectively prevent slipping on the ed e.

The particular lmateria s employed may be varied to suit varying conditlonswithout departing from the invention', as viewed-in its broa er` aspects. has been found that a base of cast iron provided with a surface layer of granular' artificial corundum, known as alundum, gives satisfactory results. However other cast metals, such as brass or bronze' or aluminum alloys,niay be used for the base, and natural Patented Apr. 12, 1910.

For most purposes itcorundum, carborundum, or similar natural or artificial material, which may be granulated and which when granulated will 'not be destroyed or seriously injured by the heat of the molten metal, may be employedfor the surface layer.

A tread surface of the character specified may be produced in accordance with a method which forms the subject-matter of a co ending application. This -method is' as fo lows: Afmold for the tread is formed, preferably in green sand. A surfaceof the mold, which is to shape a resistant, 'antislipping surface ofthe tread and particu-v larly the exposed edge of the tread, is provided with alayer of the granular hard mineral elements, this layer preferablT being caused to adhere sufficiently to the mold Surface by lightly tamping the layer into the surface.l This may be done by replacing the J pattern in the mold after the layer of granu- E lar material has been applied and then eX- erting a suitable pressure on the pattern, as by tapping the attern with the hand or a mallet so as to. orce the mrtly into the sand sur ace ofv the mold.

closed, and' the molten metal introduced into the mold, the metal being in such condition that it will penetrate the layer of granular material without ldestroying the elements thereof and bein of such a character that it will therea ter become sufliciently rigid to 'effectively resist displacement of. the mineral elements.

The layer of granular elements should Ycover the surface of the mold or be so closely arranged that, when the interstices between the elements are filledby the cast metal, the latter will be protected by the hard elements from wear or abrasion.

ranular elements A ,he pattern is .then removed, the mold Preferably, the

layer of granular elements. is made to pracf tically cover the surface of the mold and `great as the distance towhi 4m tal will penetrate. The coarser 4the grams may be given 'a substantial thickness, thel thickness of the layer being p referably as 'c the molten of the llayer the thicker it ma be. 'Ordi-` narily, the layer may be ma e to adhere suiciently by the application of ressure., as above stated. When necessary, owever, the. layer of ranular elements may beheld in place on'ie metal Vsurface by coverlngv the same with'some material the identltyof which' will be destroyed by the molten metal introduced 4into the mold. For example,

the layer of granular elements may be held in place by a piece of thin sheet metal, ne\` wire gauze, or the like, which will melt or become incorporated in the body of the molten metal introduced into the metal but not, however, until the molten metal'has ifully understood reference may filledv the mold or assumed a suiiiciently qui-` escent state to avoid the detachmentof the granular layer `from the mold surface.

The invention further consists in thel novel constructions, combinations, and improvements herein set forth.

In order that the invention ma be more e had to the accompanying drawings wherein the inventionis illustrated as 'applied to a stair tread.

Of the drawings, Figure l is a fragmentary vertical section of' a stairway equipped with treads embodying the vinvention; Fig. 2 is a 4plan view of one of the treads; and Fig; 3 is a sectional perspective view illustrating a portion of one of the parts, if desire In the embo iment of the invention illustrated the tread isformed of two parts 1 and 2 but it 4is obvious that the tread may be made of a reater or less ynumber of the form of ribs 3, and the part l isy provided with'the -ex osed edge or nosing 4,

"It is obvious that t ese raised parts may be mineral elements formin ticularly 4observe f-shppmg layer may be extended over and to the extreme edge of any formand number desired and arranged in anysuitable relationto eachother, 'or y the tread may be rovided` with a plain, surface, if desired. he upper surface of.

Vthe raised portions 3 and thesurfa'ce of the Asjshown, each 'of the parts 1s provided with raised portions -in trated, so that t ere is no danger iol Slipping on the edge ofthe tread, andby reason of the resistant nature of the layer thls exosed edge as Well as the other effective sur-e aces of the 'tread will retain theiry antivsli ing properties even though much used. W 11e the resistant layer is extremely durable, it will nevertheless eventually be worn down, particularly at those arts which re ceive t e greatest amount o wear. As the forward part ofthe tread receives the greatest amount of wear, this part is preferably made of a separate piece from the rear part;

as shown, so that 1t may be removed and replaced without disturbing the. rear part,`

both parts being removably securedto the step or other-supiort.V The parts 4ma? be removably secur to the support in desired way. In the construction shown the parts are secured lby means of screws 6 whih may pass through .openings convenient trea members between the raised portions.

any

formed in the thin portions of the Where the treads are employed in connec-4 tion with concrete stairs, the screws 'may enter suitable anchor pieces embedded the concrete.

One advantage .of the particular embodiment of the invention illustrated is that by reason of the fact that the thin portions of the tread members arenot provided with resistant surfaces, 't'he holes for the screws may be easily formed in the tread members at any desired point Aor points along their lei'igths toV suit the location of the anchor pieces. v

' Advantages other than those mentioned of the invention and of the particular embodiment thereof illustrated will be obvious to those familiar with fthe practical use of stair and similar treads.'

I claim:

l. A stair o r similar tread having an` exf posed edge, said tread com rising 'a base of' cast metal and a layer o granular'hard vfmineral elements embedded in the surface of said hase and extending substantially to'they said exposed edge thereof, said elements be-V ingof such material and'size that they will not be injured.` by the .heat of the molten V metal when casting the base and said elementsbeing so arranged as to'A prevent slip- -ping `and to are embedded from abrasion.

2r A stair or similar tread having an ex-v posed', edge, said tread comprising a base .cf cast iron anda layer of granular corundum embedded in the surface of the base and extendin Ysubstantially tothe exposededge thereof, t e grains of corundum 7being so arranged as to prevent slipping and to rotect the iron in which theyl are embedd abrasion. Y 'v 3. A stair lor similar tread having an eirposed rounded edge or no'sin said treadv comprising a base of cast meta vand a layer rotect the metal in which they f isti fromv surface and anv exposed rounded ed e 'of'` and alayer of granular corundum embedded -the 'ribs and in the surface of the edge or yand slze that they will not be injured by f -the heat of the molten metal when casting as to prevent slipping and to ,of cast metal'and'a layer of .mineral elements embedded ,in the upper surfaces of the ribs and in the surface of I,of cast iron and a layer of granular corunof granular hard mineral elements embedded in the surface of said base and extending substantially to the said extposed edge or nosing, said elements being o casting the base and said elements being so arranged as to prventslipping and to frotect the metal 1n which they are embe ded from abrasion.

4, A stair or similar tread having a ribbed nosing, said tread comprising a base o castme'tal and a layer of granular hard mineral elements embedded in the upper surfaces of nosing, said elements being of such material the base and said elements being so arrange rotect the metal 'in which they are embedded from abrasion.

5. Aistair or similar tread having la ribbed surface a'nd an exposed rounded ed e or nosing, said tread comprising a base o cast iron the edge or nosing, said elements being of such material and size that Athey will not be injured by the heatof the molten metal when casting the base and said elementsbeing so arranged as to prevent slipping and to protect the metal 1n which they are embedded fromI abrasion, and thedepressions between the ribsy being provided with perfor-ations for receiving 'the fastening devices.

- 7. A stair/or similar tread formed ofra I plurality of members each having a ribbed surface and one having an exposed rounded edge or nosing7 said tread comprisinga base dum embedded in the u per surfaces vof the ribs and in the. surface o the edge o r nosing,

such Amaterial and size that they will `not be injured bythe heat of the molten metal when said grains of corund'um being so arranged as to prevent slipping and to protect the iron Vin which they are embedded from abrasion,

and the depressions between the ribs being provided with perforations for recelving astening devices.

8. A stair or similar tread comprising a` ribbed member having 4an ex osed edge, said member comprising a base o castmetal and a layer of granular hard mineral elements embedded in the base at and in the immediate vicinity of said exposed ed e, said elements bein of such material and size that they will not e injured by the heat ofthe molten Ametal when -casting the base, and said elements being so arranged as to prevent slipping and to rotect the metal in which they are embedded froml abrasion. -1 I i9.' A stair or similar tread comprising a ribbedy member having an 'ex osed edge, said membercomprising a base o castiron and a layer of granular corundum embedded in the basein the immediate vicinity of said eX- vposed-edge, said elements being soarranged -as to prevent slipping and to protect the metal in which they are embedded from abrasion.

' 10. A stair or similar tread comprisingA ribbed member having an exposedroun edge or nosing, saidmember comprising a base ofcast metal and a layer of granular hard mineral elements embedded in the surface of said rounded edge or nosing, said elements'being of such material and size that they -Will not be.v injured by the heat of the molten metal when casting the base, and said elements being so arran ed as to prevent shpping and to protect t e metal in which they are embedded'from abrasion.

11. A stair or similar `tread .compr1s1ng a ribbed member having an exposed rounded edge or nosing, said .member comprising a base of cast iron`and a layer of granularcorundum embedded in thesurface of said rounded edge or nosin'g, the grains of corun- Adum being-so arranged as to, prevent slipping and to protect the cast iron in which they are embedded from abrasion.,

In testimony whereof, I., have signed my name to this specification', in the presence of two subscribingwitneses.

CHARLES B; JACOBS. Witnesses: EDWIN SEGER, WM. J. DoLAN. 

